POS0559 ACCELERATED WANING OF HUMORAL IMMUNE RESPONSE TO A THIRD COVID-19 VACCINATION IN PATIENTS WITH IMMUNE-MEDIATED INFLAMMATORY DISEASES
Authors: D. Mrak, F. Kartnig, D. Sieghart, E. Simader, H. Radner, P. Mandl, L. Göschl, P. Hofer, T. Deimel, I. Gessl, R. Kain, S. Winkler, J. S. Smolen, T. Perkmann, H. Haslacher, D. Aletaha, L. Heinz, M. Bonelli
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> A 3<sup>rd</sup> COVID-19 vaccination is currently recommended for patients under immunosuppression. However, a fast decline of antibodies against the SARS-CoV-2 receptor-binding domain (RBD) of the spike protein has been observed. <h3>Objectives</h3> It remains unclear whether immunosuppressive therapy affects kinetics of humoral and cellular immune responses. <h3>Methods</h3> 50 patients under immunosuppression and 42 healthy controls (HCs) received a 3<sup>rd</sup> dose of an mRNA-based vaccine and were monitored over a 12-weeks period. Humoral immune response was assessed 4 and 12 weeks after 3<sup>rd</sup> dose. Antibodies were quantified using the Elecsys Anti-SARS-CoV-2 Spike immunoassay against the receptor-binding domain (RBD) of the spike protein. SARS-CoV-2-specific T cell responses were quantified by IFN-γ ELISpot assays. Adverse events, including SARS-CoV-2 infections, were monitored over a 12-week period. <h3>Results</h3> At week 12, reduced anti-RBD antibody levels were observed in IMID patients as compared to HCs (median antibody level 5345 BAU/ml [1781 – 10208] versus 9650 BAU/ml [6633 - 16050], p &lt; 0.001). Reduction in relative antibody levels was significantly higher in IMID patients as compared to HCs at week 12 (p &lt; 0.001). Lowest anti-RBD antibody levels were detected in IMID patients who received biological diseases modifying anti-rheumatic drugs (DMARDs) or a combination therapy with conventional synthetic and biological DMARDs. Number of SARS-CoV-2-specific T cells against wildtype and Omicron variants remained stable over 12 weeks in IMID patients. No serious adverse events were reported. <h3>Conclusion</h3> Due to a fast decline in anti-RBD antibodies in IMID patients an early 4<sup>th</sup> vaccination should be considered in this vulnerable group of patients. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Daniel Mrak Consultant of: AstraZeneca, Felix Kartnig: None declared, Daniela Sieghart: None declared, Elisabeth Simader Speakers bureau: Lilly, Helga Radner Speakers bureau: Gilead, Merck Sharp and Pfizer, Peter Mandl: None declared, Lisa Göschl: None declared, Philipp Hofer: None declared, Thomas Deimel: None declared, Irina Gessl: None declared, Renate Kain Speakers bureau: Otsuka, Consultant of: AstraZeneca, Takeda Pharma, MEDahead and Janssen Cilag, Stefan Winkler: None declared, Josef S. Smolen Consultant of: AbbVie, Amgen, AstraZeneca, Astro, Bristol-Myers Squibb, Celltrion, Gilead-Galapagos, Janssen, Lilly, Pfizer, R-Pharma, Samsung, Sanofi, Chugai, Merck Sharp &amp; Dohme, Novartis-Sandoz Roche, Samsung and UCB, Grant/research support from: Abbvie, AstraZeneca, Lilly, Novartis, and Roche, Thomas Perkmann: None declared, Helmuth Haslacher Grant/research support from: Glock Health, BlueSky Immunotherapies and Neutrolis, Daniel Aletaha Speakers bureau: Abbvie, Amgen, Galapagos, Lilly, Janssen, Merck, Novartis, Pfizer, Sandoz, and Sanofi, Consultant of: Abbvie, Amgen, Galapagos, Lilly, Janssen, Merck, Novartis, Pfizer, Sandoz, and Sanofi, Grant/research support from: Abbvie, Amgen, Galapagos, Lilly, Janssen, Merck, Novartis, Pfizer, Sandoz, and Sanofi, Leonhard Heinz: None declared, Michael Bonelli Consultant of: EliLilly.